Journal
CHEMCATCHEM
Volume 12, Issue 10, Pages 2792-2800Publisher
WILEY-V C H VERLAG GMBH
DOI: 10.1002/cctc.202000327
Keywords
Power-to-methane; aerosol; alkali promotion; CO2 hydrogenation; nickel
Categories
Funding
- Netherlands Organization for Scientific Research (NWO) Gravitation program
- Netherlands Center for Multiscale Catalytic Energy Conversion (MCEC)
- Advanced Research Center Chemical Building Blocks Consortium (ARC CBBC)
- NWO
- BASF
- NWO Earth and Life Science (ALW) [824.14.002]
Ask authors/readers for more resources
In Power-to-Methane (PtM) plants, the renewable electricity supply can be stabilized by using green electrons to produce H-2 via H2O electrolysis, which is subsequently used to hydrogenate CO2 into CH4. In this work PtM is studied in a cascade fashion, from simulated solar light to methane production in an all-in-one setup, which was newly developed for this work. This setup was used to assess the effects of H-2 stream purity on the activity of Ni/SiO2 catalysts in CO2 methanation. An activity effect in downstream methanation is shown to be onset by aerosols that evolve from the electrochemical splitting of water. Small amounts of K are shown to affect CH4 production positively, but only if they are deposited in situ, via KOH aerosols. K-doped Ni/SiO2 catalysts prepared in an ex situ manner, by impregnation with a KOH solution, showed a decrease in activity, while the same amount of KOH was deposited. Operando FT-IR spectroscopy reveals that increased back-donation to CO-containing intermediates and carbonates formation likely causes catalyst deactivation in ex situ samples as often reported in literature for Ni/SiO2 catalysts. The mechanism for in situ promotion is either an increased rate in the hydrogenation of CHx (X=0-3) fragments, or a more facile water formation or desorption as CO-containing reaction intermediates are unaffected by in situ promotion. These results are relevant to PtM from a fundamental standpoint explaining the effect of potassium on nickel methanation, but also from a practical standpoint as the presented effect of in situ promotion is difficult to achieve via standard synthesis methods.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available